From the specification of French published patent application No. FR2560368A, it is known to provide a heat exchanger of this type in which the ends of the tubes are sealingly fitted in holes formed in a header plate of a water header, a casing of which is secured over the collector, and in which immobilising or locating means are also provided for resisting any relative displacement of the tube bundles with respect to the header plate. Such displacement is liable to occur in particular in a pivoting or torsional mode.
In heat exchangers of the kind just mentioned, sealing between the end portions of the tubes and edges of the holes and the header plate is generally obtained by means of a gasket of rubber or similar material, which over lies the header plate and which is formed with collar portions, with each of these collar portions being engaged between an end portion of one tube and the edge of a corresponding hole in the header plate.
When such a heat exchanger is handled either before or during its fitting into a vehicle, or when it has been fitted in the vehicle, relative movements can occur, in particular in a pivoting or torsional load, of the tube bundle with respect to the header plate. These movements, which can occur in particular in those heat exchangers having only one row of aligned tubes, are detrimental to sealing between the end portions of the tubes and the edges of the holes in the header plate.
The immobilising or locating means which are provided in the arrangement described in the above mentioned French patent specification enable a rigid connection to be made between the tube bundle and the header plate, which is thus resistant to the relative displacements mentioned above. However, in that known arrangement, the immobilising means make it necessary to form slots along the longitudinal edges of the fins, or even to provide aligned openings which are formed through the latter, and this therefore calls for the use of special fins.
In addition, the immobilising means in the document mentioned above comprise lugs which are moulded integrally with the header casing or header plate, or even with fingers which are moulded integrally with the latter. This makes it necessary to manufacture specific components by moulding in plastics material.